The present invention relates to a semiconductor device and a manufacturing method of a semiconductor device, and can be preferably used in a semiconductor device using, for example, a nitride semiconductor and a manufacturing method thereof.
In recent years, semiconductor devices using group III-V compounds, each of which has a bandgap larger than that of Si, have attracted attention. Among them, semiconductor devices using gallium nitride (GaN) are being developed, because gallium nitride is a material having advantages that: 1) the breakdown electric field is large; 2) the electron saturation velocity is large; 3) the thermal conductivity is large; 4) a good heterojunction can be formed between AlGaN and GaN; 5) gallium nitride is non-poisonous and highly safe; and the like.
Further, semiconductor devices, each of which is a power MISFET (Metal Insulator Semiconductor Field Effect Transistor) using gallium nitride because of its high withstand voltage and a high-speed switching characteristic and in each of which a normally-off operation can be performed, are being developed.
For example, Japanese Unexamined Patent Application Publication No. 2013-118343 discloses a MIS-type compound semiconductor device adopting a gate recess structure. In this semiconductor device, a recess for a gate electrode is formed in an interlayer insulating film, a passivation film, and a compound semiconductor lamination.